Ecological network analysis of energy metabolism in the Beijing-Tianjin-Hebei (Jing-Jin-Ji) urban agglomeration

China's strategy for synergetic development of the Jing-Jin-Ji urban agglomeration is providing a great opportunity for this region. The development of urban agglomeration has promoted energy transmission and transference within the urban system. Therefore, identifying the mechanisms of energy flow processes within the agglomeration is important for integrated and sustainable regional development. Using the concept of “urban metabolism”, we constructed an 18-sector network model that represented sectors and energy flow as nodes and pathways, respectively. Next, based on the multi-regional input-output table of China in 2010, we converted monetary values into physical units. Then, by combining these physical units with ecological network analysis, we detailed energy flow processes and calculated energy consumption on sectoral and regional scales. The results showed that the greatest amount of energy was consumed by industry. Beijing was the dominant integrated energy consumer, and most of this energy was consumed by the other services sector. Furthermore, the wholesale and retail sector, and the other services sector in Beijing, and the industry sectors in Tianjin and Hebei, were core sectors in the agglomeration. Tianjin and Hebei were net energy exporters, while Beijing acted as a net importer. This research provides a scientific basis for industrial structure adjustment and optimized energy utilization in the future synergetic development of the agglomeration.